rate of reaction

Question 1

rate of a chemical reaction

Answer 1

• measure the speed at which chemical occurs.
• usually measure the rate product is formed or reactants are consumed
• measure as change in concentration per unit of time
• has units of mol l-1 s-1
• formula: average reaction rate= change in concentration/ time

Question 2

A + B –> C

Answer 2

• for the reaction A + B -> C
• The rate (r) can be expressed in terms of product formation or reactant consumption
• ”-“ rate of consumption of reactant
• ”+” rate of production of product
• numerical value for r is an absolute value

Question 3

rate equalities

Answer 3

rate =ΔC/ΔT= - ΔA/ΔT = - ΔB/ΔT

Question 4

Change in rates: average rate of reaction

Answer 4

• the speed at which a reaction proceeds over a period of time (concentration of a reactant or product over time)
• Average rate of reaction typically DECREASES over time.
• Concentration of reactants decreases with time and the reaction rate usually depends on the reactant concentration.

Question 5

Graphical Analysis

Answer 5

• often graphed as concentration vs time
• 1. average rate of reaction: measured as the slope of the secant between 2 points on a graph
• 2. Instanteous rate of reaction: measured as the slope of the tangent at a single point.
• AROR: over a time interval is the absolute value of the slope of a secant (line between two points)
• IROR: the speed at which a reaction is proceeding at specific point in time. The absolute value for the slope of a tangent line (drawn at a specific point).